1 files changed, 99 insertions, 0 deletions
diff --git a/include/linux/firmware/qcom/qcom_qseecom.h b/include/linux/firmware/qcom/qcom_qseecom.h
new file mode 100644
index 000000000000..366243ee9609
--- /dev/null
+++ b/include/linux/firmware/qcom/qcom_qseecom.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Driver for Qualcomm Secure Execution Environment (SEE) interface (QSEECOM).
+ * Responsible for setting up and managing QSEECOM client devices.
+ *
+ * Copyright (C) 2023 Maximilian Luz <luzmaximilian@gmail.com>
+ */
+
+#ifndef __QCOM_QSEECOM_H
+#define __QCOM_QSEECOM_H
+
+#include <linux/auxiliary_bus.h>
+#include <linux/dma-mapping.h>
+#include <linux/types.h>
+
+#include <linux/firmware/qcom/qcom_scm.h>
+
+/**
+ * struct qseecom_client - QSEECOM client device.
+ * @aux_dev: Underlying auxiliary device.
+ * @app_id: ID of the loaded application.
+ */
+struct qseecom_client {
+	struct auxiliary_device aux_dev;
+	u32 app_id;
+};
+
+/**
+ * qseecom_scm_dev() - Get the SCM device associated with the QSEECOM client.
+ * @client: The QSEECOM client device.
+ *
+ * Returns the SCM device under which the provided QSEECOM client device
+ * operates. This function is intended to be used for DMA allocations.
+ */
+static inline struct device *qseecom_scm_dev(struct qseecom_client *client)
+{
+	return client->aux_dev.dev.parent->parent;
+}
+
+/**
+ * qseecom_dma_alloc() - Allocate DMA memory for a QSEECOM client.
+ * @client:     The QSEECOM client to allocate the memory for.
+ * @size:       The number of bytes to allocate.
+ * @dma_handle: Pointer to where the DMA address should be stored.
+ * @gfp:        Allocation flags.
+ *
+ * Wrapper function for dma_alloc_coherent(), allocating DMA memory usable for
+ * TZ/QSEECOM communication. Refer to dma_alloc_coherent() for details.
+ */
+static inline void *qseecom_dma_alloc(struct qseecom_client *client, size_t size,
+				      dma_addr_t *dma_handle, gfp_t gfp)
+{
+	return dma_alloc_coherent(qseecom_scm_dev(client), size, dma_handle, gfp);
+}
+
+/**
+ * dma_free_coherent() - Free QSEECOM DMA memory.
+ * @client:     The QSEECOM client for which the memory has been allocated.
+ * @size:       The number of bytes allocated.
+ * @cpu_addr:   Virtual memory address to free.
+ * @dma_handle: DMA memory address to free.
+ *
+ * Wrapper function for dma_free_coherent(), freeing memory previously
+ * allocated with qseecom_dma_alloc(). Refer to dma_free_coherent() for
+ * details.
+ */
+static inline void qseecom_dma_free(struct qseecom_client *client, size_t size,
+				    void *cpu_addr, dma_addr_t dma_handle)
+{
+	return dma_free_coherent(qseecom_scm_dev(client), size, cpu_addr, dma_handle);
+}
+
+/**
+ * qcom_qseecom_app_send() - Send to and receive data from a given QSEE app.
+ * @client:   The QSEECOM client associated with the target app.
+ * @req:      DMA address of the request buffer sent to the app.
+ * @req_size: Size of the request buffer.
+ * @rsp:      DMA address of the response buffer, written to by the app.
+ * @rsp_size: Size of the response buffer.
+ *
+ * Sends a request to the QSEE app associated with the given client and read
+ * back its response. The caller must provide two DMA memory regions, one for
+ * the request and one for the response, and fill out the @req region with the
+ * respective (app-specific) request data. The QSEE app reads this and returns
+ * its response in the @rsp region.
+ *
+ * Note: This is a convenience wrapper around qcom_scm_qseecom_app_send().
+ * Clients should prefer to use this wrapper.
+ *
+ * Return: Zero on success, nonzero on failure.
+ */
+static inline int qcom_qseecom_app_send(struct qseecom_client *client,
+					dma_addr_t req, size_t req_size,
+					dma_addr_t rsp, size_t rsp_size)
+{
+	return qcom_scm_qseecom_app_send(client->app_id, req, req_size, rsp, rsp_size);
+}
+
+#endif /* __QCOM_QSEECOM_H */